Naturally, the beaches are the biggest draw in Cancun with their soft, white sand and brilliant turquoise-blue water. Cancun’s Hotel Zone is really just one long beach separated from the mainland by a system of lagoons. The dazzling white sand of Cancun’s beaches is light in weight and cool underfoot even in the blazing sun. That’s because it is composed not of silica but rather of microscopic plankton fossils called disco-aster (a...